Curvy girl: Ozzy's daughter mocked The Voice judge for having a slightly fuller figure as she promoted her new fragrance Royal Desire in Munich last month

Rivals: Kelly and Christina sparred at the MTV Europe Music Awards in Edinburgh, Scotland, in 2003

Kelly and Christina have famously feuded for years.

Back at the MTV Europe Music Awards in November 2003, the network even aired a skit of Christina throwing darts at a photo of the British personality.

When she took the stage, she mocked Ozzy's daughter as well, saying: 'Oh Lord, I didn't realise it was still Halloween.'

But The Voice judge isn't the only person Kelly is sparring with over weight these days. However, given that her body is the source of ridicule might make her a bit more forgiving towards someone else.

While she was attending Amy Winehouse's funeral last week, her ex-fiance Luke Worrall posted a series of cruel tweets making fun of her figure.

He deleted them mere hours later, but a furious Kelly couldn't resist retaliating over Twitter.